Gründerzeit with future - subproject 3: Historical window and façade components

Currently there are no energetical and aesthetical windows in high quality. Two types of windows were developed that have high standards regarding design and energetical and constructional performance.

Short Description

This project is a sub project of the flagship project "Gründerzeit with future: Innovative Modernisation of Wilhelminian style "Gründerzeit" Buildings"




Starting point/ Motivation

In the field of refurbishment of "Gründerzeit"-buildings there are no window components available which have an up to date thermal performance and equal an elegant aesthetic appeal. On the other hand there are a lot of Gründerzeit buildings which have lost their aesthetic valuable elements in the facade and ended up as simple plain facades with a boring grid of unique window holes, so there is a need for new façade-components which enrich the public appearance of the building and which foster the quality of living rooms behind.

Contents and Objectives

GRUEFF will develop two different types of new window- facade elements, which base on commonly available industrial parts, with high aesthetic and energetic performance and as an integrated system up to detail drawings.

Type A shall deliver a very elegant and thermal high performing window that matches the aesthetic needs of original Gründerzeit facades with rich ornaments and without external thermal insulation.

Type B is foreseen as a new developed window-element for plain facades with standard external insulation. By its new design it shall enhance significantly the appearance in the public space and by fully integrated features like ventilation with heat recovery and shading upgrade the functionality for the occupants.


GRUEFF applies integrated team research with partners in the field of architecture, window manufacturing, civil engineering, building physics and m & e- engineers.

The research proceeds step by step starting wiht basis research with feedback loops and ending up with iterative improvement to a solution.


For type A (window replacement) the feasibility study is accomplished for 3 versions which enable different applications. Type A is documented in detail and workshop drawings, One manufactured Type A window with integrated sunshading was installed for demonstration purposes in a Gründerzeit-building.

For type B (new facade element) one final version was developed out of a series of test versions. All required detail drawings are developed, ready to be adopted for the workshop drawings of a test-building, renderings are prepared to show the range of applications.